On Monday evening, 24 November 1654, 'from around 10:30 until about 12:30 in the morning,' as he himself scrupulously recorded, Pascal had a mystical experience that changed the course of his life. Language broke down and could not bear the strain of what Pascal experienced. He could find only one word to act as an aegis or symbol of his experience, and he wrote the word in capital letters at the head of the sheet of paper on which he recorded his experience: 'FEU' - 'FIRE.'